1. Field of the Invention
The present invention relates generally to a wireless charging apparatus and method, and more particularly, to a wireless charging apparatus and method that control wireless power transmission through a non-contact wireless local communication channel.
2. Description of the Related Art
Various technologies for providing power to portable electronic products have been developed in response to increases in the release and distribution of various portable electronic products along with the development of Information Technology (IT). A technology of receiving power by using a power line was previously used, but a wireless power transmission technology capable of wirelessly receiving power is has been actively developed.
The wireless power transmission technology transmits electric energy in a form of electromagnetic wave, electromagnetic induction, or electromagnetic resonance, which wirelessly supplies power without a power line, such as an electric wire, anytime and anywhere. The wireless power transmission technology is a core technology for wirelessly charging electronic devices, wirelessly supplying or charging power to electric cars, wirelessly supplying power to a remote place, and supplying power through ubiquitous wireless sensors. The wireless power transmission technology may be used to replace conventional methods of supplying or charging power through an electric wire.
When using the wireless power transmission technology for a wireless charging apparatus, the wireless charging apparatus includes a wireless power transmitter for supplying power and a wireless power receiver for charging power to a battery. The wireless power transmitter measures a change in value of loads or a change in value of a resonance frequency in a wireless charging standby state, and detects whether an object is put on a source resonator. Further, when the object is detected, the wireless power transmitter transmits power required for charging to supply the power to the object, and identifies whether the object is an object for the wireless charging or another metal object through an authentication process such as an ID exchange. When the authentication is successfully performed, the wireless power transmitter determines the object put on the source resonator as a wirelessly rechargeable charger, that is, the wireless power receiver, and negotiates the power transmission. When the negotiation is completed, the wireless power transmitter starts wireless power supply for charging the wireless power receiver, and then identifies whether the corresponding wireless power receiver is completely charged. When the wireless power receiver is completely charged, the wireless power transmitter stops transmitting the power to the corresponding wireless power receiver.
The wireless power transmitter and the wireless power receiver perform wireless power transmission control through communication, and a communication scheme includes an in-band communication scheme or out-of-band communication scheme. The in-band communication scheme performs the wireless power transmission control by using the same frequency band as a wireless supply frequency band and a communication frequency band between the wireless power transmitter and the wireless power receiver. The out-of-band communication scheme performs the wireless power transmission control by using different frequency bands as a wireless supply frequency band and a communication frequency band between the wireless power transmitter and the wireless power receiver.
Since the wireless charging apparatus is currently applied to a portable small electronic device, components therein become smaller, and various configurations and circuit arrangement techniques are used to improve the capability thereof.
For example, the wireless charging apparatus is applied to a portable terminal that receives power from a charging pad and performs battery charging. The portable terminal employs a technique which makes sizes of components for the wireless charging small, arranges some components for the wireless charging within the portable terminal to improve the capability thereof, and connects the remaining components arranged outside the portable terminal through connection terminals.
For example, FIG. 1 illustrates a portable terminal to which a wireless charging apparatus is applied. Referring to FIG. 1, the portable terminal includes a portable terminal body 10 and an external battery cover 20. When the wireless charging apparatus is applied to the portable terminal, some components for wireless charging are included in the body 10, and remaining components 22 for wireless charging are arranged on the external battery cover 20. The wireless charging apparatus can operate through a connection between the components of the wireless charging apparatus located in the body 10 and the components of the wireless charging apparatus located in the external battery cover 20 by means of the wireless charging connection terminals.
However, the portable terminal includes other components for functions other than wireless charging, which are separately located within the body 10 and on the external battery cover 20. For example, component 26 for non-contact local communication may be separately arranged within the body 10 and on some areas of the external battery cover 20, and components for non-contact local communication may operate through connection terminals for the non-contact local communication indicated by reference numerals 15 and 25. As described above, when there are connection terminals 11, 21, 15, and 25 for wireless charging and non-contact local communication in the portable terminal, the number of connection terminals increase in production of the portable terminal, which makes a manufacturing process complex.
When the components for wireless power transmission and the components for non-contact local communication are redundant, a plurality of communication components is required, which results in inefficiency and resource waste.